A Timeline of Terrorism Warning: Incomplete Data

The recent terrorist attacks in Paris have unfortunately once again brought terrorism to the front of many people’s minds. While thinking about these attacks and what they mean in a broad historical context I’ve been curious about if terrorism really is more prevalent today (as it feels), and if data on terrorism throughout history can offer us perspective on the terrorism of today.

In particular:

Have incidents of terrorism been increasing over time?

Does the amount of attacks vary with the time of year?

What type of attack and what type of target are most common?

Are the terrorist groups committing attacks the same over decades long time scales?

Trevor writes a very good post and the visualizations are ones that you will find useful for this and other date.

However, there is a major incompleteness in Trevor’s data. If you follow the link for “comprehensive data set” and the FAQ you find there, you will find excluded from this data set:

Criterion III: The action must be outside the context of legitimate warfare activities.

So that excludes the equivalent of five Hiroshimas dropped on rural Cambodia (1969-1973), the first and second Iraq wars, the invasion of Afghanistan, numerous other acts of terrorism using cruise missiles and drones, all by the United States, to say nothing of the atrocities committed by Russia against a variety of opponents and other governments since 1970.

Depending on how you count separate acts, I would say the comprehensive data set is short by several orders of magnitude in accounting for all the acts of terrorism between 1970 to 2014.

If that additional data were added to the data set, I suspect (don’t know because the data set is incomplete) that who is responsible for more deaths and more terror would have a quite different result from that offered by Trevor.

So I don’t just idly complain, I will contact the United States Air Force to see if there are public records on how many bombing missions and how many bombs were dropped on Cambodia and in subsequent campaigns. That could be a very interesting data set all on its own.